Transmission system message format for reporting conditions from remote stations to a central station

ABSTRACT

A condition supervision system for supervising conditions of a building air conditioning system wherein processing and indication apparatus at a central station is connected over a transmission circuit to a plurality of remote stations whereby messages indicative of conditions at the remote stations are indicated at the central station. The message format used by remote stations to report the condition at a particular remote station comprises two portions. The first portion of the message identifies the data and the form of the output from a condition responsive transducer of that station. The second portion is made up of the output from the transducer; so that, when a remote station reports to the central station, the first portion of the message is used to inform a central station processing apparatus of the form of the output to be received in the second portion of the message so that a type of processing can be selected for the particular form of output in the second portion of the message.

United States Patent [151 3,636,560 Schoenwitz 1 Jan. 18, 1972 [54] TRANSMISSION SYSTEM MESSAGE FORMAT FOR REPORTING CONDITIONS FROM REMOTE STATIONS TO A CENTRAL STATION Primary Examiner-David L. Trafton AnomeyLamont B. Koontz, Francis A. Sirr and Clyde C. Blinn [72] Inventor: Frank H. W. Schoenwitz, Arlington [57] ABSTRACT Heights A condition supervision system for supervising conditions of a [73] Assigneez Honeywell Minneapolis Minn building air conditioning system wherein processing and indication apparatus at a central station is connected over a trans- [22] Filed: Oct. 13, 1969 mission circuit to a plurality of remote stations whereby messages indicative of conditions at the remote stations are in- [211 Appl' 865820 dicated at the central station. The message format used by remote stations to report the condition at a particular remote 52 0.5. Ci ..340/409, 340/150, 340/206 station comprises two portions The first portion of the [5 1] Int. Cl. ..G08b 5/22 message identifies the data and the form of the Output from a 58 Field of Search ..34o/409, 150, 147, 213, 206 condition responsive transducer Of that stalioh- The second portion is made up of the output from the transducer; so that, [56] References Cited when a remote station reports to the central station, the first portion of the message is used to inform a central station UNITED STATES PATENTS processing apparatus of the form of the output to be received in the second portion of the message so that a type of 2,919,435 Hawley X p i g can be selected f the particular f f p in 2,946,044 7/1960 Bolglano, Jr. et al. ..340/150 UX the Second portion ofthe message 3,166,74l I/l965 Spence ..340/2l3 3,3 I 2.965 4/1967 Ward ..340/l50 X 6 Claims, 4 Drawin Fi ures H [4 REMOTE STATIONS 4 INDICATION 40 l I 32 APPARATUS 43 RESISTANCE TO L l1 MRTA 2 PERIOD (T) I 4? Z I 3 TRANSDUCER l TEMP. RESPONSIVE I INTERFACE I To I a RESISTANCE ELEMENT I EQUIPMENT CONVERTER I GROZP 1' L I I J. 35 MESSAGE RECEIVING MRTAI 2 34 AND TRANSMITTING APPARATUS (MRTA) I5 i L gg To CENTRAL :1 g 42 TRANSDUCER m 31 I k i PERIOD LEASED 2| LEASED I l TO BCD LINE LINE MRTA CONVERTER INTERFACE INTERFACE I i RESISTANCE TO LEASED LINE PERIOD (TI TRANSDUCER PATENTEB III I 81972 Ki DATA 52 FORM OF TYPE D REMOTE sTATIONs Fla! I' 44 INDICATION lo 25, I I 32 I -43 I APiPfRATUS I RESISTANCE TO [4 I i GROUP MRTAI PERIOD (T) I I it] 3 TRANSDUCER lNTERFACE PERIOD TO I V TEMP. RESPONSIVE l EQUIPMENT- BCD GROUP RESISTANCE ELEMENT I CONVERTER I l 2 MESSAGE RECEIVING I 34 AND TRANSMITTING MRTA: g

APPARATus (MRTM I5 I REsIsTANCE TO 2 GROUP I 3 800 CENTRAL #3 I 42 TRANsDuCER sTATION l3 22 23 3|\ I v 4| r PERIOD LEASED 2| LEASED I I TO BCD LINE LINE MRTA CONVERTER INTERFACE INTERFACE I RESISTANCE To LEASED LINE PERIOD (T) 2 TRANSDUCER SON MESSAGE FORM; GROUP #I, STATION I/L/53 I I IQL I I I I I I I I I IH 9 ":55 n n W K 5| DATA 52 FORM OF DATA IN PERIOD FORM TYPE DATA FIG. 3 53' 50' MESSAGE FORM; GROUP #2, STATION 1 ,A

L l I I I I I I I I I I I Ul I I I I I I I I I W j W DATA ,FORM OF HUNDREDS uNITs 52 5| TYPE 52 DATA TENS DATA IN BCD FORM 50" 4 53 MESSAGE FORM; GROUP #3, STATION I QI I I I I I I I I I W QJ I I I I I J I I I I J DATA IN BCD FORM INVENTOR.

FRANK H. W. SCHOENWITZ ATTOR/VE X TRANSMISSION SYSTEM MESSAGE FORMAT FOR REPORTING CONDITIONS FROM REMOTE STATIONS TO A CENTRAL STATION REFERENCE TO COPENDING APPLICATION This invention relatesto the subject matter disclosed in copending application 864,679, now abandoned.

BACKGROUND OF THE INVENTION Transmission systems connecting a central station to a plurality of remote stations have used a message format comprising a plurality of bits in binary form, and data reported from remote stations indicative of the level of the condition being sensed has been generally transmitted in various forms. With a remote transducer having a BCD (binary coded decimal) output indicative of a sense condition, the remote station sends a message format in BCD-form to the central station and processing apparatus converts the information into appropriate units indication. With a remote transducer having a period output wherein the time between electrical pulses is indicative of the condition being sensed, the conversion of the period output to a BCD-message form takes place at the central station after the message has been sent over the transmission circuit.

The type of transducer and form of transmitted output depends upon several system design requirements. Period output transducers may be less expensive than BCD-output transducers; therefore, period to BCD-conversion is done at the central station. While period output transmission may be more desirable, transmission line capabilities may restrict period output transmission to require period to BCD-conversion at the remote station.

SUMMARY OF THE INVENTION The present invention is concerned with the manner in which a central station processing apparatus is informed of the form of the output data received from a remote station whereby the proper data processing can take place.

Specifically a transmission system for transmitting coded messages makes use of a message format having a message made up of two portions. The first portion of the message identifies (l) the data being sent in a second portion of the message, and (2) the form of the output of the data in the second portion of the message. When the central station receives the first portion of the message, the processing apparatus is placed into proper operation to process the form of output as received in the second portion of the message.

Specifically, a remote station can either have a BCD-form of output or have a period form of output, a first portion of the message is used to inform the central station processing apparatus what form of data output is available from the remote station.

The drawing comprises a plurality of figures of which:

FIG. 1 is a schematic representation of the system showing the central station connected over a plurality of channels to remote stations, each of which has a condition responsive device;

FIG. 2 is a particular reporting message format comprising a first portion in binary code and a second pulsating output or period output form;

FIG. 3 is another reporting message format comprising a second portion in binary coded decimal output form and,

FIG. 4 is another reporting message format comprising a second portion in binary coded decimal output form.

DESCRIPTION OF THE INVENTION REferring to FIG. 1 a central station or panel is connected to a plurality of groups of remote stations shown as groups No. 1, No. 2 and No. 3 each of which have a panel ll, 12 and 13 respectively. Associated with each group panel are a plurality of remote stations 14. Only one remote station is shown associated with each group for explanation purposes. The remote groups No. l and No. 2 are connected to the central station over a single transmission channel 15. The remote group No. 3 is connected over a single transmission channel 20 which is made up of a leased line, such as a telephone line 21 interposed between group No. 3 and the central station. The remote stations of groups No. l and No. 2 would be located in a building or buildings which could be connected by conventional electric circuit such as coaxial cable to make up channel 15. When the remote stations such as those of group No. 3 are geographically located such that panel 13 is connected to the central station 10 over a leased telephone line, certain interface equipment 22 and 23 is used to make the signal transmission over channel 20 compatible with the requirements of the leased telephone line 21.

The central station has message receiving and transmitting apparatus 24 for transmitting and receiving messages to and from the message receiving and transmitting apparatus 25, 30, and 31 of groups No. 1, No. 2, and No. 3. While the type of communication means used between the central station and the groups of remote stations is no part of this invention, for explanation purposes one particular type of message format using serially coded messages comprising a plurality of bits in binary form is disclosed. Such a message format when used in a supervision and control system for a building air conditioning system is disclosed in a copending James R. Berrett et al. application Ser. No. 864,679.

Specifically, remote station 1 of group No. 1 has connected thereto a temperature responsive resistance element 32 which is connected to a resistance to period transducer 33. Transducer 33 has a pulsating type or form of output which is connected to panel 11 and the period or the time between adjacent pulses is indicative of the resistance and thus temperature of element 32. Remote station 1 of group No. 2 comprises a temperature responsive resistance element 34 which is connected to a resistance to binary coded decimal transducer 35 for providing a BCD form of output indicative of the temperature of element 34. Station 1 of group No. 3 has a temperature responsive resistance element 40 connected to a resistance to period transducer 41 which is similar to station 1 of group No. 1. As group No. 3 is connected to the central station over a leased line 21, the output of transducer 41 is connected to a period to BCD-converter 42 which converts the period, to a BCD form of output indicative of the temperature of element 40.

The central station has an indication or control apparatus 43 for indicating the data received from the various remote stations. When the central station receives an incoming message from one of the remote groups, the central station message receiving and transmitting apparatus 24 supplies the data to the processing apparatus 44 which is connected to apparatus 43. Processing apparatus 44 comprises a period to BCD-converter 4S and certain interface equipment 46. If the incoming data is in BCD-form, the interface equipment 46 feeds the data output or second portion of the message directly to apparatus 43. If the incoming data is in a period form, the data output portion of the message is fed through the period to BCD-converter 45, to convert the output to a BCD- form to be then fed to apparatus 43. Interface equipment 46 is informed by the message format as to the type of data received from the remote stations, as well as, the form of the data.

The message form or format used to send data from the message receiving and transmitting apparatus 25, 30, and 31 of any one of the groups No. 1, No. 2, and No. 3, respectively, to the message receiving and transmitting apparatus 24 of the central station comprises two portions. A first portion identifies (l) the data type, and (2) the form of the output of the data to be received in the second portion of the message. Upon receiving the message, the central station interface equipment 46 can determine how the data received in the second portion of the message will be handled or processed before being supplied to apparatus 43. For explanation purposes, different message forms are shown in FIGS. 2, 3, and 4 representing data received from the remote stations of groups No. 1, No.2, and No.3 of FIG. 1.

Referring to FIG. 2, an example of a message form comprises the first portion 50 made up of l2 bits wherein six bits shown at 51 provide the type of data and informs the apparatus 43 that the data from station 1 of group No. 1 is a temperature. The last bit 52 of the first portion 50 of the message is used to inform the processing apparatus 44 of the form of the output to be transmitted in the second portion 53 of the 1 message. With a mark in bit 52, apparatus 44 is informed that the form of the output in the second portion 53 of the message will be in a period form; that is, a plurality of pulses 55 will be received which are obtained from resistance to period transducer 33 of remote station 1 in group No. 1. As described in connection with FIG. 1, the period 60, is indicative of the resistance of element 32 and thus the temperature to which element 32 is exposed. When the second portion 53 of the message of FIG. 2 is received by apparatus 44, the interface apparatus 46 is informed by bit 52 in the message that the form of output is of a period form and must be converted to BCD by converter 45 before the message is fed to apparatus 43.

Another example of message form which is received from station I of group No. 2 in FIG. 1 is shown in FIG. 3 wherein the first portion 50' of the message has a data type 51 to inform the central station that the data received is a temperature. Bit 52 has a space for informing apparatus 44 that the form of output received in the second portion 53 of the message is in BCD-form and apparatus 46 directs the message to apparatus 43 for readout. Specifically, the second portion 53' f the message shows the data with three BCD-groups of four bits wherein the first group 60 is the hundreds group, a second group 61 is the tens group, and a third group 62 is a units group.

Another example of message form is shown in FIG. 4 for the output received from station 1 of group No. 3 in FIG. 1. As the station is a temperature measurement station with a period of transducer 41, similar to station 1 of group No. 1, the output received by the central station would normally be in the form of a period output, as shown with the message in FIG. 2. The station is connected over a telephone line 21 to the central station and since the telephone line can not receive a highfrequency signal which is needed for transmitting a pulsating or period output of a resistance to period transducer 41, the period output is converted to a BCD-output. The portion 50" of the message in FIG. 4 has the data type to inform apparatus 44 and then apparatus 43 that data is a temperature. Data form bit 52" is a space to indicate that the form of the output in the second portion 53" of the message is a BCD-form with a similar group of three four-bit groups as disclosed in FIG. 3. When the message of FIG. 4 is received after being transmitted over leased line 21, apparatus 46, upon interpreting the bit 52" as to the form of output, directs the second portion 53" of the message to apparatus 43 without making use of the period to BCD-converter 45.

OPERATION OF THE INVENTION When the conditions or temperatures of the various stations associated with groups No. 1, No. 2, and No. 3 are transmitted to the central station for processing the remote groups may send data in period output form or BCD-output form. The form of output depends upon the system design requirements that is, the transducer associated with each remote station or the type of channel over which the data must be transmitted.

The message format provides for the first portion of the message to inform the central station of the form of the output to be received in the second portion of the message whereby the central station can process the data in the second portion of the message. Since a remote station may have an output in period form or BCD-form, the message receiving and transmitting apparatus, such as apparatus 25 of the group panel 11, makes use of a bit in the first portion of the message to identify the type of output to be received in the second portion of the message so that central station processing apparatus 44 is able to process the data in the proper manner before use by indication apparatus 43.

The embodiments of the invention in which an exclusive property or right is claimed are defined as follows:

1. In a condition system for responding to conditions of a building air conditioning system comprising,

a central station comprising:

air conditioning system output responsive apparatus,

message receiving apparatus for receiving messages comprising a first portion and a second portion wherein said first portion identifies the data type and the form of said second portion,

message processing apparatus for processing said messages comprising a plurality of means for processing said second portion of said messages,

means connecting said message processing apparatus to said message receiving apparatus and said air conditioning output responsive apparatus,

a plurality of groups of remote stations, and single channel transmission means connecting said central station to each of said groups of stations, each of said plurality of groups of remote stations having;

message transmitting apparatus for transmitting messages comprising a first portion and a second portion wherein said first portion identifies the data type and the form of said second portion,

a plurality of transducer means, each of said transducer means being associated with a station and having an input and output circuit means, said output circuit means having an output of one of a plurality of forms determined by said transducer means,

air conditioning system condition responsive means connected to said input, and

circuit means connecting said output to said message transmitting apparatus for providing an output for said second portion of said message, said first portion of said message identifying the data type and the form of output of said second portion of said message whereby upon said message receiving apparatus at said central station receiving said message, said first portion is used to select one of said plurality of means for processing of said output of said second portion of said message by said processing apparatus to provide an output of the condition of said responsive means to said output responsive apparatus at said central station.

2. The invention of claim 1 wherein, said output for at least one of said transducer means is in binary coded decimal form indicative of said condition and said output of at least one of said transducer means is a pulsating output wherein the period between pulses is indicative of said condition,

said first portion of said message having at least one bit to identify whether said output is either in binary coded decimal form or a pulsating output whereupon said processing apparatus processes said second portion of said message.

3. The invention of claim 1 wherein said output of at least one transducer means provides a second portion of said message in binary coded decimal form,

said output of at least one other transducer means provides a second portion of said message in period form,

said processing apparatus is adapted by said first portion of a message to process a binary coded decimal message form, and

said processing apparatus is adapted by said first portion of a message of said other transducer to process a period message form.

4. The invention of claim 1 wherein said messages from said remote stations have a plurality of bits in binary form with at least one of said bits of said first for at least one of said stations may only carry messages in binary code form and at least one bit in said first portion of said message informs said processing apparatus that said transmission in said second portion is in binary code form.

6. The invention of claim 4 wherein said first portion comprises l2 bits in binary form. 

1. In a condition system for responding to conditions of a building air conditioning system comprising, a central station comprising: air conditioning system output responsive apparatus, message receiving apparatus for receiving messages comprising a first portion and a second portion wherein said first portion identifies the data type and the form of said second portion, message processing apparatus for processing said messages comprising a plurality of means for processing said second portion of said messages, means connecting said message processing apparatus to said message receiving apparatus and said air conditioning output responsive apparatus, a plurality of groups of remote stations, and single channel transmission means connecting said central station to each of said groups of stations, each of said plurality of groups of remote stations having; message transmitting apparatus for transmitting messages comprising a first portion and a second portion wherein said first portion identifies the data type and the form of said second portion, a plurality of transducer means, each of said transducer means being associated with a station and having an input and output circuit means, said output circuit means having an output of one of a plurality of forms determined by said transducer means, air conditioning system condition responsive means connected to said input, and circuit means connecting said output to said message transmitting apparatus for providing an output for said second portion of said message, said first portion of said message identifying the data type and the form of output of said second portion of said message whereby upon said message receiving apparatus at said central station receiving said message, said first portion is used to select one of said plurality of means for processing of said output of said secOnd portion of said message by said processing apparatus to provide an output of the condition of said responsive means to said output responsive apparatus at said central station.
 2. The invention of claim 1 wherein, said output for at least one of said transducer means is in binary coded decimal form indicative of said condition and said output of at least one of said transducer means is a pulsating output wherein the period between pulses is indicative of said condition, said first portion of said message having at least one bit to identify whether said output is either in binary coded decimal form or a pulsating output whereupon said processing apparatus processes said second portion of said message.
 3. The invention of claim 1 wherein said output of at least one transducer means provides a second portion of said message in binary coded decimal form, said output of at least one other transducer means provides a second portion of said message in period form, said processing apparatus is adapted by said first portion of a message to process a binary coded decimal message form, and said processing apparatus is adapted by said first portion of a message of said other transducer to process a period message form.
 4. The invention of claim 1 wherein said messages from said remote stations have a plurality of bits in binary form with at least one of said bits of said first portion indicative of the data type of the data of said second portion and another of said bits in said first portion indicative of the data form of said second portion, whereby one of said plurality of means for processing of said second portion of said message depends upon said another bit.
 5. The invention of claim 1 wherein said transmission means for at least one of said stations may only carry messages in binary code form and at least one bit in said first portion of said message informs said processing apparatus that said transmission in said second portion is in binary code form.
 6. The invention of claim 4 wherein said first portion comprises 12 bits in binary form. 